The images are not so great, when I go to get a zoom it becomes out of focus. I don’t see anything that suggests these are reproductions. Does something make you feel that they are not authentic?
In the 60’s China was making reproductions with nickel silver and plastic stones. These have no markings or signatures. Was that common back then?
I have never heard of that or seen something like that. It is common to not have hallmarks in this timeframe. If you can retake the pictures and put up in focus I would be able to tell, but these look legit.